*{margin: 0;padding: 0}
html,body{
    height: 100%;
    background: black;
    position: relative
}
div{
    position: absolute;
    top: 0;
    left: 0;
    width: 200px;
    height: 50px;
    background: black;
}
div>span{
    background: red;
    height: 50px;
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
}
#kaishi{
    position: absolute;
    top: 0;
    right: 35px;
}
#zanting{
    position: absolute;
    top: 0;
    right: 0;
}